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| Separating substances from liquids a hundred years ago was still a novel chore and not even as easy as a car insurance comparison is today. |
Air and Gases in Water.-A considerable amount of air generally exists in water, and is taken up by the gills of fishes, assisting them to accomplish the proper aeration, or rather oxygenation, of their blood. The air usually mingled with water may be expelled by boiling, but is absorbed again if the boiled water is agitated with access of the atmosphere.
Now, that particular segment doesn't make a great deal of sense in the grand sense of things, but it would appear that the author is trying to talk about the purification or the impurities that can be found or removed from water.
Additional Articles from the Book of Medicine:
- THE LEG; ITS MECHANISM AND ITS WONDERFUL ENDOWMENTS
Leg Muscle.- In every part of the human brain there is witnessed ample evidence of design, beauty of architecture, great skill, Finnish workmanship, and a perfect adaptability to the duties he performed. This fact is strikingly illustrated in the beautifully executed color plates to which attention is now drawn, join as it does, at a glance, a thick, strong, muscular instruments employed in the manifold intricacies involved in the act of human locomotion. This exquisitely artistic anatomical plate represents a front view of the pie, leg and foot, and of the 54 fleshy lovers which give form, shape, symmetry, strength and mobility to this useful member of the body. Quite a number of the most important are seen exposed to view, after the scan and fatty tissues have been removed. We are deeply impressed with their large size and great strength, both of which correspond with the requirements demanded the very work which the lake is called onto the form.
In many ways this initial section of the book seems to read less like a medical book and more like a sales pitch trying to convince people to like the human body and accept the ‘beauty’ of the anatomy of the body. This sales pitch like style is reminiscent of reading a sales catalog for floor tile or a flyer on the latest model of Fords or something. Its more like copy writing than medical text.
- Use of the Leg Muscles
Use of the Leg Muscles. – Is and the muscles observed in this plate are the principal instruments for carrying out the behest of the will in the act of walking, running, leaping, climbing, and the graceful, gliding motions of the interesting and captivating waltz; and although we see a complicated piece of machinery, yet there is perfect order. Harmony, promptitude and exactness prevail, not only in the skillful manner in which they are individually and collectively range, but in the action of the different muscles, each one of which performs its duty either independently of, or in connection with, its fellow lever, and that, too, without interfering in the slightest degree with the functions of the others.
Later on in this book we will start to see some examples of muscle building exercise. There was some strength equipment used back then that largely consisted of free weights and many of the exercises could still be employed today despite the fact that many of the exercises have been perfected for form.
- How Mosquitoes Develop
How mosquitoes develop.-A Female mosquito lays from 200 to 300 eggs at a time and always in standing water, as the eggs must have still water and no matter how filthy the water, it will not destroy the eggs or prevent their development.
This is such a basic description that it is almost not worth the ink it is printed with. But if you take a look at Wikipedia, you might get just a simple sense of how much our knowledge has grown. Below is what constitutes a basic reference on the biology of Mosquito from Wikipedia. Where are previous knowledge of a mosquito could be measured in a couple dozen bits, it might now take a few megs of ram to contain our knowledge.
Anatomy
The mosquito is composed of a head, thorax, and abdomen. The head contains two compound eyes and proboscis. The proboscis is a piercing mouthpart used to suck blood from its prey. The mosquito’s head is mostly eye. Each eye is made up of many tiny lenses forming a compound eye. This type of eye allows a very big field of vision that easily detects movement. Next is the thorax. The thorax has one pair of wings and one pair of halteres. The thorax also has markings that are used in the identification of the mosquito. The abdomen, or gut, expands as it ingests its prey’s blood. The abdomen also has many markings that are used to identify the mosquito species.
[edit] Life cycle and feeding habits
Culex mosquito larvae
In its life cycle the mosquito undergoes complete metamorphosis, going through four distinct stages: egg, larva, pupa, and adult, first described by the Greek philosopher Aristotle.[28]
[edit] Egg
Female mosquitoes lay their eggs one at a time or together in rafts of fifty or more eggs on the surface in fresh or any stagnant water. Anopheles and Aedes mosquitoes do not make egg rafts but lay their eggs separately. Culex, Culiseta, and Anopheles lay their eggs on water while Aedes lay their eggs on damp soil that is periodically flooded by water. Most eggs hatch into larvae in about 48 hours. A female mosquito may lay a raft of eggs every third night during its life span if it can find enough blood to develop the eggs.
[edit] Larval stage
The hatching eggs turn into larvae that live in the water, coming to the surface to breathe. The first larval stage is known as the first instar. As they grow, they shed or moult their skin about four times, growing larger after each moulting. After the first molt they are second instars, then third, then fourth. Most larvae use siphon tubes going to the water surface for breathing and hang on or near the water surface. Anopheles larvae do not have a siphon and typically lie parallel to the water surface. The larvae eat micro-organisms and organic matter in the water for food. Mosquito larvae, commonly called “wigglers” or “wrigglers”, must live in water from 7 to 14 days depending on the water’s temperature. At their last moult they may be up to 1 cm or 1/2 inch long. In each stage they may be eaten by other insects or fish. Mosquito larvae in the genus Toxorhynchites eat other mosquito larvae.
The length of the first three stages (or instars) is dependent on the species and temperature, with lower temperatures increasing the length of the development stage.[29] Culex tarsalis may complete its life cycle in 14 days at 20 C (68 F) and only ten days at 25 C (77 F). Some species have a life cycle of as little as four days, whereas in other species some adult females can live through the winter, laying their eggs in the spring. Many species of mosquito live their adult stage in roughly two weeks to two months. The larvae are the “wrigglers” found in puddles or water-filled containers. These breathe air through a siphon at the tail end. The pupae, or “tumblers”, are nearly as active as the larvae, but breathe through thoracic “horns” attached to the thoracic spiracles. Most larvae feed on micro-organisms, but a few are predatory on other mosquito larvae. Some mosquito larvae, such as those of Wyeomyia live in unusual situations. These mosquito wigglers live either in the water collected in epiphytic bromeliads or inside water stored in carnivorous pitcher plants. Larvae of the genus Deinocerites live in crab holes along the edge of the ocean. On the fourth molt the larva changes into a pupa.
[edit] Pupa
The pupae are lighter than water and float on the surface as the mosquito larva metamorphoses (changes) into an adult mosquito in about two days. Pupae do not have mouths and therefore do not feed. This is important to know from a larviciding point of view because most larvicide has to be ingested by the mosquito. A surface oil or mmf (monomolecular film) should be applied to the breeding site as a means of suffocating the pupa.
[edit] Adult
The newly emerged adult must rest on the surface of the water for a short time to allow itself to dry and all its parts to harden before it can fly. This requires still water: mosquitoes do not breed in fast-moving water.
The total time to go through all four stages depends on the temperature and the type of mosquito, but typically takes 14 days or less in warmer weather. In various species the time varies from 4 to 30 days.
Most mosquito species outside of the tropics overwinter as eggs, but many overwinter as larvae or adults. Mosquitoes of the genus Culex (a vector for St. Louis encephalitis) overwinter as mated adult females.
Most mosquitoes stay fairly close to the ground and do not range too far from where they were born, but may be dispersed long distances by wind. Mosquitoes are not strong flyers, making only 1-2 km/h (1-1.5 mph); therefore, an electric fan may suffice as an effective mosquito screen. They feed mostly in the mornings and evenings and occasionally at night, avoiding the heat of the day. During the day they usually find somewhere cool to rest. Mosquitoes can tend to live over puddled water or grassy areas.
Mosquito biting finger
Only female mosquitoes bite animals to get blood needed to produce eggs. Male mosquitoes do not bite, but both the male and female feed on the nectar of flowers for food. In most female mosquitoes, the mouth parts form a long proboscis for piercing the skin of mammals (or in some cases birds or even reptiles and amphibians) to suck their blood. As opposed to a syringe’s typically smooth needle, the mosquito proboscis is highly serrated, which leaves a minimal number of points of contact with the skin being pierced — this reduces nerve stimulation to the point where the “bite” is typically not felt at all. (See the Mosquitoes and health section below for an explanation on the swelling). The females require protein for egg development and laying, and since the normal mosquito diet consists of nectar and fruit juice, which has no protein, most females must drink blood to lay eggs. Males differ from females, with mouth parts not suitable for blood-sucking.
The female mosquitoes locate their next blood donor victims primarily through scent. They are extremely sensitive to the carbon dioxide in exhaled breath, as well as to substances found in sweat and various body odours such as 1-octen-3-ol. They are believed to be able to track potential prey for tens of meters. Some people attract more mosquitoes than others, apparently based on how they “smell” to a mosquito. Mosquitoes can also detect heat, so they can find warm-blooded mammals and birds very easily once they get close enough. Repellents like DEET work by disorienting the mosquito as it gets close to its potential next meal but do not kill mosquitoes. Surprisingly this works about 95% of the time.[citation needed]
Male mosquitoes may tend to be smaller than females, with features such as feathered antennae and conspicuous external genitalia.
